from django.core.paginator import Paginator, EmptyPage, PageNotAnInteger
from django.shortcuts import render, get_object_or_404
# 导入发送邮件函数
from django.core.mail import send_mail
from .models import Post 
# 导入表单类
from .forms import EmailPostForm
# 导入表单类，此处增加了导入评论表单类的代码
from .forms import EmailPostForm, CommentForm
from taggit.models import Tag
from django.db.models import Count
from django.contrib.postgres.search import SearchVector
from .forms import EmailPostForm, CommentForm, SearchForm

def post_list(request, tag_slug=None):  # 注意函数参数request即请求  
    posts = Post.published.all() 
    tag = None
    # 如果请求中有tag_slug，则获取标签并按标签过滤文章数据
    if tag_slug:
        # 获取标签
        tag = get_object_or_404(Tag, slug=tag_slug)
        # 按标签过滤文章
        posts = posts.filter(tags=tag)
    paginator = Paginator(posts, 3)
    page = request.GET.get('page')
    try:
        posts = paginator.page(page)
    except PageNotAnInteger:
        posts = paginator.page(1)
    except EmptyPage:
        posts = paginator.page(paginator.num_pages)
    return render(request, 'blog/post/list.html', {'posts': posts, 'page': page, 'tag': tag}) # 返回blog/base.html模板文件# Create your views here.
def post_detail(request, year, month, day, post):
   post = get_object_or_404(Post, slug=post, status='published',
                            publish__year=year,
                            publish__month=month,
                            publish__day=day)
   return render(request, 'blog/post/detail.html', {'post': post})
def post_share(request, post_id):
 # 获取要分享的文章信息
   post = get_object_or_404(Post, id=post_id, status='published')
 # 设置发送状态为未发送
   sent = False
 # 如果请求是POST表示有提交表单
   if request.method == 'POST':
 # 通过EmailPostForm表单类获取请求中的表单数据后保存到form中
      form = EmailPostForm(request.POST)
 # 如果表单数据验证通过则发送邮件并将状态设置为已发送
      if form.is_valid():
 # 发送邮件，稍后完成
 # 发送状态设置为真
         cd = form.cleaned_data
      # 构建请求路径
         post_url = request.build_absolute_uri(post.get_absolute_url())
      # 构建邮件标题
         subject = f"{cd['name']} recommends you read " \
                  f"{post.title}"
      # 构建邮件正文
         message = f"Read {post.title} at {post_url}\n\n" \
                  f"{cd['name']}\'s comments: {cd['comments']}"
      # 发送邮件
         send_mail(subject, message, '1651709315@qq.com',
                  [cd['to']])
      # 发送状态设置为真
         sent = True
   else:
      # 如果表单数据验证未通过将表单设置为空
      form = EmailPostForm()
      # 渲染分享文章模板，并将文章、表单、发送状态信息传递给文章分享模板
   return render(request, 'blog/post/share.html', {'post': post,'form': form,'sent': sent})
def post_detail(request, year, month, day, post):
    post = get_object_or_404(Post, slug=post, status='published',
                             publish__year=year,
                             publish__month=month,
                             publish__day=day)                      
    comments = post.comments.filter(active=True)
    new_comment = None
    if request.method == 'POST':
        comment_form = CommentForm(data=request.POST)
        if comment_form.is_valid():
            new_comment = comment_form.save(commit=False)
            new_comment.post = post
            new_comment.save()
    else:
        comment_form = CommentForm()
    post_tags_ids = post.tags.values_list('id', flat=True)
    # 找到包含当前文章任意标签的文章集合（除当前文章外）
    similar_posts = Post.published.filter(tags__in=post_tags_ids)\
        .exclude(id=post.id)
    # 对相似文章按照相同标签数量进行排序，取前4个，相同标签数量使用聚合函数Count
    # 计算后保存在same_tags中，以便后续使用
    similar_posts = similar_posts.annotate(same_tags=Count('tags'))\
        .order_by('-same_tags','-publish')[:4]
    
    return render(request,'blog/post/detail.html',{'post': post,'comments': comments,
                                                'new_comment': new_comment,'comment_form': comment_form,'similar_posts': similar_posts})
def post_search(request):
 form = SearchForm()
 query = None
 results = []
 # 如果请求中有query字段则获取表单中的数据进行处理
 if 'query' in request.GET:
    # 获取表单
    form = SearchForm(request.GET)
    # 如果表单中的数据验证通过，即有效，则获取并处理
    if form.is_valid():
        # 获取搜索内容保存下来
        query = form.cleaned_data['query']
        # 根据标题和正文字段构建搜索向量并生成搜索字段，再根据搜索内容筛选出匹配内容保存
        results = Post.published.annotate(
            search=SearchVector('title', 'body')
            ).filter(search=query)
        # 将搜索结果渲染到搜索模板并返回
 return render(request, 
 'blog/post/search.html', {
 'form': form,
 'query': query,
 'results': results
 })

